Imprint apparatus and article manufacturing method using same

ABSTRACT

An imprint apparatus molds an uncured resin on a substrate and cures the resin to form a pattern of the cured resin on the substrate. The apparatus includes a mold holding unit that holds the mold, a substrate holding unit that holds the substrate, a deforming unit that deforms the mold held by the mold holding unit into a convex shape toward the substrate, a driving unit that changes an attitude of the mold or the substrate during a releasing operation in which the mold deformed into the convex shape is released from the resin to thereby make the position of a contact region at which the mold is brought into contact with the resin movable, a measuring unit that acquires image information indicating a state of the contact region, and a control unit configured to control the operation of the driving unit based on the image information.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an imprint apparatus and an articlemanufacturing method using the same.

2. Description of the Related Art

As the demand for microfabrication of semiconductor devices or MEMSincreases, not only a conventional photolithography technology but alsoa microfabrication technology in which an uncured resin on a substrateis molded by a mold to thereby form a resin pattern on the substratehave been receiving attention. This technology is also referred to as an“imprint technology”, by which a fine structure with dimensions of a fewnanometers can be formed on a substrate. One example of imprinttechnologies includes a photo-curing method. An imprint apparatusemploying the photo-curing method first applies an ultraviolet curableresin (imprint material, photocurable resin) to a shot region (imprintregion) on a substrate (wafer). Next, the resin (uncured resin) ismolded by a mold. After the ultraviolet curable resin is irradiated withultraviolet light for curing, the cured resin is released from the mold,whereby a resin pattern is formed on the substrate.

Since the internal atmosphere of the imprinting apparatus employing theaforementioned technology is basically gas (ambient air), air bubblesmay be entrapped in a resin when a mold is pressed against the resin ona substrate. If the resin is cured with air bubbles entrapped therein,there is a high probability that defects will occur in the pattern to beformed. In order to avoid the occurrence of such pattern defects,Japanese Patent Laid-Open No. 2009-518207 discloses a method forremoving gas between a mold and a resin in which the mold is temporarilydeflected into a convex shape toward the substrate, a resin on thesubstrate is pressed against the mold in this state, and the mold isgradually restored to a flat surface so as to press the entire patternsurface against the resin. According to the method, gas present betweenthe mold and the resin may be discharged from the inside to the outside,and thus, air bubbles entrapped in a resin may be reduced.

Furthermore, in the conventional imprint apparatus, if the mold isentirely released from the resin at one time, a large releasing stressis momentarily applied to the interface (contact portion) between themold and the cured resin. Such a stress may cause distortion of thepattern to be formed in the resin, resulting in defects in the pattern.In contrast, in the apparatus disclosed in Japanese Patent Laid-Open No.2009-518207, the mold is temporarily deflected into a convex shape whenthe mold is released from the resin in the same manner as when the moldis pressed against the resin. With this arrangement, the mold isgradually released from the periphery toward the center of thepattern-formed region of the cured resin. Consequently, the forcerequired for a mold releasing is made smaller than that when nodeflection is produced in the mold, and thus, the abrupt occurrence ofstress can be avoided.

Here, as with the apparatus disclosed in Japanese Patent Laid-Open No.2009-518207, if the mold is gradually deformed and released from theperiphery toward the center of the pattern-formed region of the curedresin, the contact region between the mold and the resin graduallydecreases and eventually disappears when the mold is completely releasedfrom the resin. However, the centroid of the contact region may bedisplaced from the center of the pattern-forming region in the course ofthe releasing operation depending on the deflection state of the mold orthe layout of the pattern formed in the mold. Thus, if the position ofthe contact region is offset in the XY plane as described above, warpageof the mold increases at the portion where the distance between theboundary of the contact region and the end of the pattern-forming regionto is close. The inclination of the concave and convex pattern (patternsection) formed in the mold increases with an increase of warpage of themold. Consequently, the concave and convex pattern formed in the moldmay be in contact with the pattern formed over the resin, resulting inthe occurrence of defects such as pattern deformation, pattern damage,or the like.

SUMMARY OF THE INVENTION

Accordingly, the present invention provides an imprint apparatus whichis advantageous for suppressing the occurrence of pattern defects.

According to an aspect of the present invention, an imprint apparatusthat molds an uncured resin on a substrate using a mold and cures theresin to thereby form a pattern of the cured resin on the substrate isprovided that includes a mold holding unit configured to hold the mold;a substrate holding unit configured to hold the substrate; a deformingunit configured to deform the mold held by the mold holding unit into aconvex shape toward the substrate; a driving unit configured to changean attitude of the mold or the substrate during a releasing operation inwhich the mold that has been deformed into the convex shape is releasedfrom the resin to thereby make the position of a contact region at whichthe mold is brought into contact with the resin movable; a measuringunit configured to acquire image information indicating a state of thecontact region; and a control unit configured to control the operationof the driving unit based on the image information.

According to the present invention, an imprint apparatus which isadvantageous for suppressing the occurrence of pattern defects may beprovided.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating the configuration of an imprintapparatus according to a first embodiment of the present invention.

FIGS. 2A and 2B are diagrams illustrating the state of the imprintapparatus according to the first embodiment prior to the centroidadjustment.

FIG. 3 is a flowchart illustrating the sequence of operation in amold-releasing step.

FIGS. 4A and 4B are diagrams illustrating the state of the imprintapparatus according to the first embodiment during the centroidadjustment.

FIGS. 5A and 5B are diagrams illustrating the state of an imprintapparatus according to a second embodiment prior to the centroidadjustment.

FIGS. 6A and 6B are diagrams illustrating the state of the imprintapparatus according to the second embodiment during the centroidadjustment.

FIGS. 7A and 7B are diagrams illustrating the state of an imprintapparatus according to a third embodiment.

FIG. 8 is a diagram illustrating the state of an imprint apparatusaccording to a fourth embodiment prior to the centroid adjustment.

FIGS. 9A and 9B are reference diagrams relating to the operation controlof a mold drive mechanism according to the fourth embodiment.

FIGS. 10A to 10C are diagrams illustrating the state of a conventionalimprint apparatus in a mold-releasing step.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will now bedescribed with reference to the accompanying drawings.

First Embodiment

Firstly, a description will be given of an imprint apparatus accordingto a first embodiment of the present invention. FIG. 1 is a diagramillustrating the configuration of an imprint apparatus. The imprintapparatus of the present embodiment is an apparatus that molds anuncured resin on a wafer (on a substrate), i.e., a substrate to betreated, using a mold to thereby form a resin pattern on the wafer,which is used in the manufacture of devices such as semiconductordevices and the like as articles. Note that the imprint apparatus of thepresent embodiment is an apparatus employing a photo-curing method. Inthe following drawings, a description will be given where the Z axis isaligned parallel to the optical axis of an irradiation system thatirradiates ultraviolet light onto a resin on a wafer, and mutuallyorthogonal axes X and Y are aligned in directions in a planeperpendicular to the Z axis. Firstly, an imprint apparatus 1 includes alight irradiation unit 2, a mold holding mechanism 3, a wafer stage 4,an application unit, and a control unit 5.

The light irradiation unit 2 irradiates a mold 6 with ultraviolet light7 during imprint processing. The light irradiation unit 2 is constitutedby a light source (not shown) and an optical element that adjusts theultraviolet light 7 emitted from the light source to light suitable forimprinting. Note that, in the present embodiment, the light irradiationunit 2 is provided for employing a photo-curing method. If athermosetting method is employed, a heat source unit for curing athermosetting resin may be provided instead of the light irradiationunit 2.

The outer peripheral shape of the mold 6 is rectangular and the mold 6includes a pattern section (e.g., the concave and convex pattern of acircuit pattern or the like to be transferred) 6 a which isthree-dimensionally formed on the surface facing a wafer 10. Also, thematerial of the mold 6 is a material such as quartz or the like throughwhich the ultraviolet light 7 can pass. Furthermore, for ease ofdeformation as described below, the mold 6 may be of a shape in which acavity (concave portion) of a circular planer shape having a certaindepth is formed on the surface on which the ultraviolet light 7 isirradiated.

Firstly, the mold holding mechanism 3 has a mold chuck (mold holdingunit) 11 that holds the mold 6 and a mold drive mechanism 12 that holdsthe mold chuck 11 and moves the mold 6 (the mold chuck 11). The moldchuck 11 may hold the mold 6 by suctioning/attracting the outerperipheral region of the surface of the mold 6 irradiated with theultraviolet light 7 using a vacuum suction force/an electrostatic force.For example, if the mold chuck 11 holds the mold 6 using a vacuumsuction force, the mold chuck 11 is connected to an externally installedvacuum pump (not shown), and attachment/detachment of the mold 6 isswitched by turning the vacuum pump ON/OFF. Also, each of the mold chuck11 and the mold drive mechanism 12 has an aperture region at the centralportion (the inside thereof) such that the ultraviolet light 7 emittedfrom the light irradiation unit 2 is irradiated toward the wafer 10. Alight transmission member (e.g. glass plate) 14 is installed within theaperture region such that a space 13 enclosed by a part of the apertureregion and the mold 6 is sealed, and the pressure in the space 13 isadjusted by a pressure adjusting device (deforming unit) 15 including avacuum pump or the like. The pressure adjusting device 15 sets thepressure in the space 13 higher than the external pressure when the mold6 is pressed against a resin 16 on the wafer 10 so that the patternsection 6 a is deflected into a convex shape toward the wafer 10 and thepattern section 6 a is brought into contact with the resin 16 from thecentral portion of the pattern section 6 a. With this arrangement, gas(air) is prevented from being entrapped between the pattern section 6 aand the resin 16 so that the resin 16 can be filled in the every cornerof the convex and concave portion of the pattern section 6 a. While, inthe present embodiment, the pressure adjusting device 15 serves as adeforming unit configured to deform a mold into a convex shape, thedeforming unit is not limited to the pressure adjusting device 15 butmay be any unit provided that it can deform a mold into a convex shape.Furthermore, the mold holding mechanism 3 has a magnification correctionmechanism (not shown) that corrects the shape of the mold 6 (the patternsection 6 a) by imparting an external force or displacement to the sidesurface of the mold 6. The magnification correction mechanism isinstalled at the mold 6-holding side of the mold chuck 11.

The mold drive mechanism 12 moves the mold 6 in each axis direction soas to selectively press the mold 6 against the resin 16 on the wafer 10or release the mold 6 from the resin 16. The mold drive mechanism 12 isconstituted by a coarse movement stage (coarse movement drive system) 17and a fine movement stage (fine movement drive system) 18. The coarsemovement stage 17 is driven a long distance mainly in the Z-axisdirection. On the other hand, the fine movement stage 18 follows thecoarse movement stage 17 and is finely driven mainly in six-axis (X, Y,Z, ωx, ωy, and ωz) directions. Examples of an actuator employable forthe mold drive mechanism 12 include a linear motor, an air cylinder, andthe like. The pressing operation and the releasing operation performedby the imprint apparatus 1 may be realized by moving the mold 6 in theZ-axis direction, may be realized by moving the wafer stage 4 in theZ-axis direction, or may also be realized by moving both the mold 6 andthe wafer stage 4 relative to each other.

The wafer 10 is, for example, a single crystal silicon substrate or aSOI (Silicon on Insulator) substrate, and an ultraviolet curable resin(hereinafter referred to as “resin”) 16, which is molded by the patternsection 6 a formed in the mold 6, is applied on the treatment surface ofthe wafer 10.

The wafer stage (substrate holding unit) 4 holds the wafer 10 andexecutes position matching between the mold 6 and the resin 16 when themold 6 is pressed against the resin 16 on the wafer 10. The wafer stage4 has a wafer chuck 19 that holds the wafer 10 by a suction force and astage drive mechanism 20 that holds the wafer chuck 19 by a mechanicalunit and is movable in each axis direction. The stage drive mechanism 20is also constituted by a coarse movement stage (coarse movement drivesystem) 21 and a fine movement stage (fine movement drive system) 22. Inthis case, the coarse movement stage 21 is driven a long distance mainlyin the XY plane. On the other hand, the fine movement stage 22 followsthe coarse movement stage 21 and is finely driven mainly in six-axis (X,Y, Z, ωx, ωy, and ωz) directions. Examples of an actuator employable forthe stage drive mechanism 20 include a linear motor, a planar motor, andthe like.

The application unit (not shown) is installed near the mold holdingmechanism 3 and applies the resin (uncured resin) 16 to the wafer 10.Here, the resin 16 is a photocurable resin (imprint material) having theproperty of being cured by receiving the irradiation of the ultravioletlight 7, and is appropriately selected depending on various conditionssuch as the manufacturing process of semiconductor devices or the like.The amount of the resin 16 to be ejected from the ejection nozzle of theapplication unit is also appropriately determined by a desired thicknessof the resin 16 to be formed on the wafer 10, the density of the patternto be formed, or the like. The “pattern-forming region (shot)” used inthe following description has substantially the same area as that of theapplied region of the resin 16 for convenience.

The control unit 5 may control the operation, adjustment, and the likeof the components of the imprint apparatus 1. The control unit 5 isconstituted by a computer or the like and is connected to the componentsof the imprint apparatus 1 through a line so as to execute control ofthe components by a program or the like. The control unit 5 of thepresent embodiment controls at least the operation of the driving unitsuch as the mold holding unit 3 or the like and the pressure adjustingdevice 15. Note that the control unit 5 may be integrated with the restof the imprint apparatus 1 (provided in a shared housing) or may beprovided separately from the rest of the imprint apparatus 1 (providedin a separate housing).

Also, the imprint apparatus 1 includes a measuring device (measuringunit) 23 that grasps the state of the contact region when the mold 6(the pattern section 6 a) is brought into contact with the resin 16 onthe wafer 10. The measuring device (measuring unit) 23 is installedabove the mold holding mechanism 3, that is, upstream of the directionin which the ultraviolet light 7 is irradiated. The measuring device 23is an imaging device such as a CCD camera or the like, and acquires thecontact region as image information in this case. Furthermore, theimprint apparatus 1 may also include an alignment measurement system, amold conveyance mechanism that conveys the mold 6 from the exterior ofthe apparatus to the mold holding mechanism 3, a substrate conveyancemechanism that that conveys the wafer 10 from the exterior of theapparatus to the substrate conveyance mechanism, and the like, none ofwhich are shown.

Next, a description will be given of imprint processing performed by theimprint apparatus 1. Firstly, the control unit 5 places and attaches thewafer 10 to the wafer chuck 19 on the wafer stage 4 using the substrateconveyance mechanism, and then moves the wafer stage 4 to theapplication position of the application unit. Next, as an applicationstep, the application unit applies the resin 16 to a pattern-formingregion which is a predetermined area to be processed of the wafer 10.Next, the control unit 5 moves the wafer stage 4 such that thepattern-forming region on the wafer 10 is placed in a position directlybelow the pattern section 6 a formed in the mold 6. Next, the controlunit 5 drives the mold drive mechanism 12 so as to press the mold 6against the resin 16 on the wafer 10 (mold-pressing step). By pressingthe mold 6 against the resin 16 on the wafer 10, the resin 16 is filledin the convex and concave portion of the pattern section 6 a.

Under this condition, as a curing step, the control unit 5 causes thelight irradiation device 2 to emit the ultraviolet light 7 from the topsurface of the mold 6, and cures the resin 16 by the ultraviolet light 7that has been transmitted through the mold 6. Then, after the resin 16is cured, the control unit 5 drives the mold drive mechanism 12 again tothereby release the mold 6 from the resin 16 (mold-releasing step). Bythe aforementioned steps, a three dimensionally shaped pattern (layer)of the resin 16 following the convex and concave portion of the patternsection 6 a is formed on the surface of the pattern-forming region onthe wafer 10. Such a sequence of imprint operations is conducted two ormore times while changing the pattern-forming region by driving thewafer stage 4 to thereby be able to form a plurality of patterns of theresin 16 on one wafer 10.

In particular, in the mold-pressing step and the mold-releasing step,the control unit 5 deforms (deflects) the mold 6 into a convex shapetoward the wafer 10 by the pressure adjusting device 15 as describedabove. Here, for comparison, a description will be given of a releasingoperation performed by a conventional imprint apparatus. FIGS. 10A to10C are schematic diagrams illustrating the state of the conventionalimprint apparatus during the releasing operation. In particular, FIG.10A is a diagram illustrating the state in the course of releasing amold 102 (a pattern section 103) from a resin layer 101, which is apattern-forming region formed on the wafer 100 during the releasingoperation. In general, when the mold 102 is released from the wafer 100,the mold 102 is subjected to a force in a direction away from the wafer100, i.e., the upper direction along the Z axis. At the same time, inthe contact region where the pattern section 103 is in contact with(fixedly attached to) the resin layer 101, the mold 102 is subjected toa releasing stress in a direction toward the wafer 100, i.e., the lowerdirection along the Z axis. Therefore, in the conventional imprintapparatus, the mold 102 is deformed into a convex shape toward the wafer100 as shown in FIG. 10A, and thus, the pattern section 103 is graduallyreleased from the periphery toward the center of the resin layer 101,resulting in avoiding the abrupt occurrence of a releasing stress. Thecontact region between the pattern section 103 and the resin layer 101gradually decreases with the progress of the releasing operation, andeventually disappears when the pattern section 103 is completelyreleased from the resin layer 101.

However, in the conventional imprint apparatus, depending on thedeflection state of the mold 102 or the layout of the pattern formed inthe mold 102, the centroid of the contact region may be displaced fromthe center of the resin layer 101 in the course of the releasingoperation. FIG. 10B is a plan view illustrating the state of the contactregion in such a case. For example, if the position of a contact region104 is offset in the XY plane, that is, if the centroid 105 of thecontact region 104 is displaced from the center 106 of the resin layer101, warpage of the mold 102 increases at a portion where the distancebetween the boundary 107 of the contact region 104 and the end 101 a ofthe resin layer 101 is close. The inclination of the pattern section 103formed in the mold 102 also increases with an increase in warpage of themold 102. FIG. 10C is an enlarged cross-sectional view illustrating thevicinity of the boundary 107 of the contact region 104. As describedabove, the concave and convex pattern 103 a of the pattern section 103may be in contact with a pattern 101 a formed on the resin layer 101,resulting in the occurrence of defects such as deformation, damage, orthe like of the pattern 101 a. Accordingly, the imprint apparatus 1 ofthe present embodiment adjusts the position of the centroid of thecontact region as appropriate during the releasing operation such thatthe position of the contact region is not offset in the XY plane.

FIGS. 2A and 2B are schematic diagrams illustrating the state of thecontact region prior to the centroid adjustment in a mold-releasingstep. In particular, FIG. 2A is a cross-sectional view illustrating thestate of the imprint apparatus 1 corresponding to that shown in FIG. 1,where the mold 6 is in a deformed state, and FIG. 2B is a plan viewillustrating the state of a contact region 24 between the patternsection 6 a and the resin (resin layer) 16 at this time. Also, FIG. 3 isa flowchart illustrating the sequence of operations performed by theimprint apparatus 1 in the mold-releasing step. Firstly, in themold-releasing step, the control unit 5 acquires image information aboutthe contact region 24 using a measuring device 23 while the patternsection 6 a is being released from the resin 16 (step S100). Next, thecontrol unit 5 calculates the position (plane coordinates) of a centroid25 of the contact region 24 based on the acquired image information(step S101). The position of the centroid 25 can be calculated byreplacing the acquired area of the contact region 24 with, for example,a polygon, a circle, an ellipse, or the like as appropriate. Note thatthe control unit 5 calculates the area of the resin 16 applied on thewafer 10, that is, the position (plane coordinates) of a center 26 ofthe pattern-forming region prior to calculation of the centroid 25.Next, the control unit 5 compares the position of the calculatedcentroid 25 with that of the calculated center 26 (step S102). Then, thecontrol unit 5 drives the fine movement stage 18, which is the drivesystem (driving unit) of the mold drive mechanism 12, such that theposition of the centroid 25 is always directed toward (matched to) theposition of the center 26 during the releasing operation (step S103). Atthis time, the control unit 5 changes the angles ωx and ωy around the XYaxis of the mold holding surface in the fine movement stage 18 whilemoving the coarse movement stage 17 of the mold drive mechanism 12upward in the Z-axis direction. Subsequently, the control unit 5 repeatsthe sequence of operations at a certain frequency (NO in step S104). Ifthe control unit 5 determines that the releasing operation has beencompleted (YES in step S104), the sequence of operations is ended (stepS104).

FIGS. 4A and 4B are schematic diagrams illustrating the state of thecontact region during the centroid adjustment in a mold-releasing step.In particular, FIG. 4A is a cross-sectional view illustrating the stateof the imprint apparatus 1 corresponding to that shown in FIG. 2, wherethe fine movement stage 18 is in a drive state, and FIG. 4B is a planview illustrating the state of the contact region 24 between the patternsection 6 a and the resin (resin layer) 16 at this time. For example, asshown in FIG. 4A, the control unit 5 changes the angle ωy around the Yaxis of the mold holding surface of the mold 6 with respect to the finemovement stage 18 to thereby change the attitude of the mold 6 (thepattern section 6 a) held by the fine movement stage 18 via the moldchuck 11. Here, the amount of change in each of the angles ωx and ωy isadjusted based on the offset amount between the centroid 25 and thecenter 26 in the XY plane. The control unit 5 adjusts the angles basedon the calculated offset amount, and thus, the position of the centroid25 is moved as shown in FIG. 4B so as to be matched with the position ofthe center 26. Also, the control unit 5 sets the calculation timing ofthe centroid 25 in advance such that the accuracy in controlling theposition of the centroid 25 is ensured and the amount of change in theangle of the mold holding surface of the fine movement stage 18 isprevented from being excessively large. For example, if apattern-forming region has the size of 20 mm×30 mm and a time requiredfor releasing is 0.1 sec, it is preferable that the control unit 5executes the calculation of the centroid 25 at intervals of 1 msec. Thecontrol unit 5 calculates the centroid 25 at such timing andfeedback-controls the amount of change in the angle of the mold holdingsurface of the fine movement stage 18 so as to maintain the accuracy incontrolling the position of the centroid 25.

Here, the driving force for the fine movement stage 18 required for moldreleasing decreases with a decrease in the area of the contact region 24as the releasing operation progresses. In contrast, when the controlunit 5 controls the driving force for the fine movement stage 18 so asto be constant, the pattern section 6 a may be rapidly peeled off fromthe resin 16 with decreasing the area of the contact region 24,resulting in the occurrence of pattern defects. Thus, it is preferablethat the control unit 5 calculates the moving speed at a boundary 27 ofthe contact region 24 and controls the driving force for the finemovement stage 18 such that the moving speed is kept constant. In thiscase, even if the fine movement stage 18 is not driven such that theposition of the centroid 25 is always directed toward the position ofthe center 26, the occurrence of pattern defects due to a rapid peel-offcan be suppressed.

As described above, the fine movement stage 18 is driven such that theposition of the centroid 25 is always directed toward the position ofthe center 26 during the releasing operation, and thus, the contactregion 24 can be prevented from being offset in the XY plane. Thus,since the mold 6 is uniformly deflected from the center 26 in themold-releasing step, the inclination of the pattern section 6 a does notlocally increase, and thus, the occurrence of pattern defects can besuppressed. Furthermore, since the contact region 24 gradually decreaseswithout being located off-center in the XY plane as the releasingoperation progresses, the moving speed at the boundary 27 of the contactregion 24becomes symmetrical based on the center 26. Thus, the movingspeed of the contact region 24 does not become locally too high at theboundary 27 during the releasing operation. Consequently, a portion atwhich the pattern section 6 a is rapidly peeled off from the resin 16 isnot likely to occur, and thus, the occurrence of pattern defects can besuppressed from the viewpoint of such a mold-releasing speed.

As described above, according to the present embodiment, an imprintapparatus which is advantageous for suppressing the occurrence ofpattern defects may be provided.

Although, in the present embodiment, the fine movement stage 18 on themold 6 side is employed as a driving unit that drives the position ofthe centroid 25 of the contact region 24 so as to be directed toward theposition of the center 26 of the resin 16, the fine movement stage 22 onthe wafer 10 side may also be employed. In this case, the coarsemovement stage 21 and the fine movement stage 22 of the stage drivemechanism 20 operate in accordance with the coarse movement stage 17 andthe fine movement stage 18 of the mold drive mechanism 12, respectively,in the aforementioned description.

Second Embodiment

Next, a description will be given of an imprint apparatus according to asecond embodiment of the present invention. FIGS. 5A and 5B areschematic diagrams illustrating the state of an imprint apparatus 30according to the present embodiment prior to the centroid adjustment ina mold-releasing step. In particular, FIG. 5A is a cross-sectional viewillustrating the configuration of the imprint apparatus 30. In FIG. 5,the same elements as those in the imprint apparatus 1 of the firstembodiment shown in FIG. 1 are designated by the same referencenumerals, and the explanation thereof will be omitted. A feature of theimprint apparatus 30 lies in the fact that a mold chuck 32 having aplurality of suction grooves 31 provided on the suction surface thereofis employed as a driving unit that drives the position of the centroid25 of the contact region 24 so as to be directed toward the position ofthe center 26 of the resin 16. In this case, a mold drive mechanism 33of the present embodiment, which corresponds to the mold drive mechanism12 of the first embodiment, may be a unitary drive mechanism that ismovable at least in the Z-axis direction instead of one having two drivesystems which are a coarse movement stage and a fine movement stage.Likewise, a stage drive mechanism 34 of the present embodiment, whichcorresponds to the stage drive mechanism 20 of the first embodiment, mayalso be a unitary drive mechanism that is movable at least in the XYaxis direction instead of one having two drive systems which are acoarse movement stage and a fine movement stage.

FIG. 5B is a plan view illustrating the configuration of a mold chuck 32as seen from the mold 6 side and the suction state of the mold chuck 32in this case. By way of example, the mold chuck 32 has three suctiongrooves 31 arranged in parallel from the inside toward the outside oneach of four regions (a first region 35 a to a fourth region 35 d) of asuction surface 35 in the XY plane. These suction grooves 31 include afirst suction groove 31 a, a second suction groove 31 b, and a thirdsuction groove 31 c which are arranged at the first region 35 a in the Xaxis direction and a fourth suction groove 31 d, a fifth suction groove31 e, and a sixth suction groove 31 f which are arranged at the secondregion 35 b opposite to the first region 35 a. Furthermore, the suctiongrooves 31 include a seventh suction groove 31 g, an eighth suctiongroove 31 h, and a ninth suction groove 31 i which are arranged at thethird region 35 c in the Y axis direction and a tenth suction groove 31j, an eleventh suction groove 31 k, and a twelfth suction groove 311which are arranged at the fourth region 35 d opposite to the thirdregion 35 c. Each of these suction grooves 31 is connected to a vacuumpump 36 via a switching mechanism. When the mold 6 is held by suction,the control unit 5 controls the switching the ON/OFF of suction producedby each of these suction grooves 31 independently of one another. Here,in the example shown in FIG. 5B, the control unit 5 sets the suctionproduced by two suction grooves 31, which are the first suction groove31 a in the X axis direction and the fourth suction groove 31 d oppositeto the first suction groove 31 a, to “ON”. In FIG. 5B, the suctiongrooves 31 in which vacuum suction is switched “ON” are denoted in blackfor ease of explanation.

On the other hand, FIGS. 6A and 6B are schematic diagrams illustratingthe state of the imprint apparatus 30 according to the presentembodiment during the centroid adjustment in a mold-pressing step. Inparticular, FIG. 6A corresponds to FIG. 5A and FIG. 6B corresponds toFIG. 5B. In the first embodiment, the control unit 5 controls theposition of the centroid 25 so as to be always directed toward theposition of the center 26 by driving the fine movement stage 18 of themold drive mechanism 12 in step 5103 in the sequence of operations shownin FIG. 3. In contrast, in the present embodiment, the control unit 5controls the position of the centroid 25 so as to be always directedtoward the position of the center 26 by switching a portion in whichvacuum suction is switched “ON” from among the plurality of suctiongrooves 31 provided in the mold chuck 32. For example, in the exampleshown in FIG. 6B, the control unit 5 changes the suction state shown inFIG. 5B to the suction state in which the suction produced by the firstsuction groove 31 a remains “ON”, but the suction produced by the fourthsuction groove 31 d is switched “OFF” and the suction produced by thefifth suction groove 31 e positioned outwardly adjacent to the fourthsuction groove 31 d is switched “ON”. At this time, selection of thesuction grooves 31 is adjusted based on the offset amount between thecentroid 25 of the contact region 24 and the center 26 in the XY plane.As described above, the suction operation of a plurality of suctiongrooves 31 is switched independently of one another. Consequently, theattitude of the pattern section 6 a is changed with a change in thedeflected shape of the mold 6 so that the position of the centroid 25 ofthe contact region 24 can be moved during the releasing operation. Withthis arrangement, according to the present embodiment, the same effectsas those of the first embodiment can be obtained.

Third Embodiment

Next, a description will be given of an imprint apparatus according to athird embodiment of the present invention. FIGS. 7A and 7B are schematicdiagrams illustrating the state of an imprint apparatus 40 according tothe present embodiment prior to the centroid adjustment and during thecentroid adjustment in a mold-releasing step. In particular, FIG. 7A isa cross-sectional view illustrating the state of the imprint apparatus40 prior to the centroid adjustment. In FIG. 7A, the same elements asthose in the imprint apparatus 1 of the first embodiment shown in FIG. 1are designated by the same reference numerals, and the explanationthereof will be omitted. A feature of the imprint apparatus 40 lies inthe fact that a moving mechanism 43 that moves a mold 41 in the XY axisdirection while holding the mold 41 by suction using a mold chuck 42 isemployed as a mechanism that drives the position of the centroid 25 ofthe contact region 24 so as to be directed toward the position of thecenter 26 of the resin 16. Also in this case, a mold drive mechanism 44of the present embodiment, which corresponds to the mold drive mechanism12 of the first embodiment, may be a unitary drive mechanism that ismovable at least in the Z-axis direction instead of one having two drivesystems which are a coarse movement stage and a fine movement stage.Likewise, a stage drive mechanism 45 of the present embodiment, whichcorresponds to the stage drive mechanism 20 of the first embodiment, mayalso be a unitary drive mechanism that is movable at least in the XYaxis direction instead of one having two drive systems which are acoarse movement stage and a fine movement stage.

Firstly, the outer shape of the mold 41 of the present embodiment andthe shape of a pattern section 41 a thereof are the same as comparedwith those of the mold 6 of the aforementioned embodiment, but the mold41 of the present embodiment has a different shape of an outer peripheryincluding a suction surface with respect to the mold chuck 42. In otherwords, the central portion of the mold 41 is thin so as to be readilydeformed into a convex shape toward the wafer 10, and the outerperiphery is formed by a thick wall portion 41 b. Consequently, the mold41 may be of a shape in which a cavity (concave portion) of a circularplaner shape having a certain depth is formed on the central portion ofthe surface onto which the ultraviolet light 7 is irradiated. Incontrast, the moving mechanism 43 is installed in, for example, the molddrive mechanism 44 and moves the mold 41 to the XY axis direction byindependently imparting an external pressure to four wall surfaces ofthe wall portion 41 b. As shown in FIG. 7A, the moving mechanism 43 mayinclude, for example, a pair of abutting rods 46 (46 a and 46 b) thatare in contact with the inside and outside of the wall portion 41 b suchthat the abutting rods 46 are driven by an actuator installed within themoving mechanism 43 in the XY axis direction.

On the other hand, FIG. 7B is a cross-sectional diagram illustrating thestate of the imprint apparatus 40 during the centroid adjustment. In thepresent embodiment, the control unit 5 controls the position of thecentroid 25 so as to be always directed toward the position of thecenter 26 by appropriately adjusting the amount of the four abuttingrods 46 to be pushed out by the moving mechanism 43. For example, in theexample shown in FIG. 7B, the control unit 5 changes the state of theabutting rods 46 shown in FIG. 7A to the state in which one of theabutting rods 46 remains unchanged in the same state but the other ofthe abutting rods 46 is pushed out so as to make the wall portion 41 bface inward. At this time, the amount of the abutting rod 46 pushed outis adjusted based on the offset amount between the centroid 25 of thecontact region 24 and the center 26 in the XY plane. As described above,the deflected shape of the mold 41 is changed by applying an externalpressure to the mold 41 using the moving mechanism 43. Consequently, theattitude of the pattern section 41 a is changed so that the position ofthe centroid 25 of the contact region 24 can be moved during thereleasing operation. With this arrangement, according to the presentembodiment, the same effects as those of the first embodiment can beobtained.

Fourth Embodiment

Next, a description will be given of an imprint apparatus according to afourth embodiment of the present invention. FIG. 8 is a schematicdiagram illustrating the state of an imprint apparatus 50 according tothe present embodiment prior to the centroid adjustment in amold-releasing step. In FIG. 8, the same elements as those in theimprint apparatus 1 of the first embodiment shown in FIG. 1 aredesignated by the same reference numerals, and the explanation thereofwill be omitted. A feature of the imprint apparatus 50 lies in the factthat the imprint apparatus 50 further includes a load measurement unit51 in addition to the components provided in the imprint apparatus ofthe embodiments and suppresses the wafer 10 from being floated up fromthe wafer chuck 19 during the releasing operation based on the measuredvalue of the load measurement unit 51. In particular, it is preferablethat the load measurement unit 51 is capable of measuring the loadacting on the mold 6 during the releasing operation. For example, theload measurement unit 51 is a measurement unit such as a load cell orthe like, and is disposed between the mold drive mechanism 12 and afixation unit (e.g., bridge surface plate) (not shown), which isprovided in the imprint apparatus 50, for supporting the mold drivemechanism 12. As in the measuring device 23, the load measurement unit51 is connected to the control unit 5.

In the mold-releasing step of the present embodiment, the control unit 5firstly acquires image information about the contact region 24 using themeasuring device 23 and calculates the area of the contact region 24based on the acquired image information as in the embodiment.Furthermore, the control unit 5 causes the load measurement unit 51 tomeasure a load on the mold 6 and acquires the measured value. Here, thearea of the contact region 24 based on the image information acquired bythe measuring device 23 is represented by “Sc”, a load on the mold 6based on the measured value obtained by the load measurement unit 51 isrepresented by “Fm”, and a suction pressure applied by the wafer chuck19 when the wafer 10 is held by suction is represented by “−pw”. Duringthe releasing operation, the load Fm acts in the direction along whichthe wafer 10 is released from the wafer chuck 19 via the contact region24. At this time, when the load Fm is less than a suction force (a valuein which the suction pressure is multiplied by the contact area: pw·Sc)generated by the wafer chuck 19, where the suction force acts on theregion in the backside of the wafer 10 opposed to the contact region 24,the wafer 10 is normally held by suction by the wafer chuck 19. However,when the load Fm is greater than the suction force pw·Sc, a force actingin the direction along which the wafer 10 is released from the waferchuck 19 becomes greater than a force for suctioning the wafer 10 to thewafer chuck 19. Consequently, the wafer 10 floats up from the waferchuck 19. Accordingly, in the present embodiment, the control unit 5controls the operation of the mold drive mechanism 12 during thereleasing operation so as to maintain the relationship of Fm<pw·Sc inthe mold-releasing step.

FIGS. 9A and 9B are reference diagrams relating to the operation controlof the mold drive mechanism 12 at this time. In particular, FIG. 9A is aplan view illustrating a change in the contact region 24 accompanyingthe progress of the releasing operation. As described above, the mold 6is deflected toward the wafer 10 in the convex shape and is graduallypeeled off from the end toward the center of the resin 16 during thereleasing operation. In other words, as shown in FIG. 9A, when thereleasing operation further progresses for the contact region 24, whichis at a certain point during the releasing operation, with the elapse oftime, the range to be released narrows down as shown by the contactregion 24 a. The faster the moving speed of the contact region 24 at itsboundary when the mold 6 is released from the resin 16, the wider therange to be released over a period of time is, resulting in an increasein the load Fm acting on the mold 6. Thus, the control unit 5 controlsthe relative speed upon releasing the mold 6 from the resin 16 (thewafer 10), that is, the speed for elevating the mold 6 in the Z-axisdirection by the mold drive mechanism 12 in the present embodiment, tothereby properly change the moving speed of the contact region 24 at itsboundary. With this arrangement, the load Fm acting on the mold 6 can beadjusted. According to the present embodiment, the same effects as thoseof the embodiment can be obtained and the wafer 10 can be suppressedfrom being floated up from the wafer chuck 19 in the mold-releasingstep.

In particular, the effects of the present embodiment are preferablyproduced at a shot S that is present at a specific position on the wafer10. FIG. 9B is a plan view illustrating the positions of three shots S1,S2, and S3 on the wafer 10 as an example. When imprint processing isperformed for the shot S, which is located relatively toward the end ofthe wafer 10, such as the shot S2 or the shot S3, the present embodimentis particularly preferable. In other words, if the lifting of the wafer10 can be suppressed at the shot S that is located at the end of thewafer 10, a decrease in the suction force of the wafer chuck 19 due tothe external air flow into the gap between the wafer 10 and the waferchuck 19 can also be suppressed. With this arrangement, the imprintapparatus 50 can avoid a positional shift of the wafer 10 with respectto the wafer chuck 19 or a peel-off of the wafer 10 from the wafer chuck19 in advance.

(Article Manufacturing Method)

A method for manufacturing a device (semiconductor integrated circuitelement, liquid display element, or the like) as an article may includea step of forming a pattern on a substrate (wafer, glass plate,film-like substrate, or the like) using the imprint apparatus describedabove. Furthermore, the manufacturing method may include a step ofetching the substrate on which a pattern has been formed. When otherarticles such as a patterned medium (storage medium), an opticalelement, or the like are manufactured, the manufacturing method mayinclude another step of processing the substrate on which a pattern hasbeen formed instead of the etching step. The article manufacturingmethod of the present embodiment has an advantage, as compared with aconventional article manufacturing method, in at least one ofperformance, quality, productivity and production cost of an article.

While the embodiments of the present invention have been described withreference to exemplary embodiments, it is to be understood that theinvention is not limited to the disclosed exemplary embodiments. Thescope of the following claims is to be accorded the broadestinterpretation so as to encompass all such modifications and equivalentstructures and functions.

This application claims the benefit of Japanese Patent Application No.2011-194583 filed Sep. 7, 2011, and Japanese Patent Application No.2012-111419 filed on May 15, 2012, which are hereby incorporated byreference herein in their entirety.

1-11. (canceled)
 12. An imprint apparatus that forms a pattern of animprint material on a substrate using a mold, the imprint apparatuscomprising: an imaging device configured to obtain an image of theimprint material of a contact region at which the mold is brought intocontact with the imprint material; and a control unit configured tochange an angle of a pattern section of the mold with respect to asurface of the substrate, based on the image obtained by the imagingdevice during a releasing operation in which the mold is released fromthe imprint material.
 13. The imprint apparatus according to claim 12,further comprising: a deforming unit configured to deform the mold intoa convex shape toward the substrate.
 14. The imprint apparatus accordingto claim 12, further comprising: a driving unit configured to change theangle of the pattern section of the mold with respect to the surface ofthe substrate; wherein the control unit is further configured tocalculate a moving speed of a boundary of the contact region of theimprint material during the releasing operation based on the image andto control the driving unit such that the moving speed is kept constant.15. The imprint apparatus according to claim 12, further comprising: adriving unit configured to change the angle of the pattern section ofthe mold with respect to the surface of the substrate; wherein thedriving unit is an actuator that is provided in a mold holding mechanismand is configured to change an angle of a holding surface of the mold inthe mold holding mechanism.
 16. The imprint apparatus according to claim12, further comprising: a driving unit configured to change an angle ofa pattern section of the mold with respect to the surface of thesubstrate; wherein the driving unit is an actuator that is provided in asubstrate holding unit and is configured to change an angle of a holdingsurface of the substrate in the substrate holding unit.
 17. The imprintapparatus according to claim 12, further comprising: a driving unitconfigured to change the angle of the pattern section of the mold withrespect to the surface of the substrate; wherein the driving unitincludes a mold holding mechanism and comprises a plurality of suctiongrooves configured to hold the mold by suction and a switching mechanismconfigured to switch a suction state of each of the plurality of thesuction grooves independently of one another.
 18. The imprint apparatusaccording to claim 12, further comprising: a load measurement unitconfigured to measure a load applied to the mold, wherein the controlunit is further configured to calculate an area of the contact regionduring the releasing operation based on the image, and control arelative speed between the substrate and the mold during the releasingoperation such that the load does not exceed a value in which a suctionpressure applied by a substrate holding unit is multiplied by the areaof the contact region.
 19. An imprint apparatus that forms a pattern ofan imprint material on a substrate using a mold, the imprint apparatuscomprising: a mold holding mechanism configured to hold the mold; asubstrate holding unit configured to hold the substrate; an imagingdevice configured to obtain an image of a contact region at which themold deformed into a convex shape toward the substrate is brought intocontact with the imprint material; a driving unit configured to changean angle of a holding surface of the mold in the mold holding mechanismwith respect to a holding surface of the substrate in the substrateholding unit; and a control unit configured to control the driving unitsuch that the angle is changed, based on the image obtained by theimaging device during a releasing operation in which the mold isreleased from the imprint material.
 20. The imprint apparatus accordingto claim 19, further comprising: a deforming unit configured to deformthe mold held by the mold holding mechanism into the convex shape towardthe substrate.
 21. The imprint apparatus according to claim 19, whereinthe control unit is further configured to calculate a moving speed of aboundary of the contact region during the releasing operation based onthe image and to control the driving unit such that the moving speed iskept constant.
 22. The imprint apparatus according to claim 19, whereinthe driving unit is an actuator that is provided in the mold holdingmechanism and is configured to change the angle of the holding surfaceof the mold in the mold holding mechanism.
 23. The imprint apparatusaccording to claim 19, wherein the driving unit is an actuator that isprovided in the substrate holding unit and is configured to change theangle of the holding surface of the substrate in the substrate holdingunit.
 24. The imprint apparatus according to claim 19, wherein thedriving unit includes the mold holding mechanism and comprises aplurality of suction grooves configured to hold the mold by suction anda switching mechanism configured to switch a suction state of each ofthe plurality of the suction grooves independently of one another. 25.The imprint apparatus according to claim 12, further comprising: a loadmeasurement unit configured to measure a load applied to the mold,wherein the control unit is further configured to calculate an area ofthe contact region during the releasing operation based on the image,and control a relative speed between the substrate and the mold duringthe releasing operation such that the load does not exceed a value inwhich a suction pressure applied by the substrate holding unit ismultiplied by the area of the contact region.